1. Field of the Invention
The present invention relates to a pre-treating method for plating a Fe—Mn—Al alloy surface. More particularly, the present invention relates to a pre-treating method for activating a Fe—Mn—Al alloy surface by means of cleaning with a high-concentrated basic solution and vibrating with ultrasonic engergy that may enhance adhesion of the Fe—Mn—Al alloy surface for plating.
2. Description of the Related Art
Generally, nickel and chromium components contained in stainless steel are always rare and costly so Fe—Mn—Al alloy has replaced stainless steel. In mining industry, nickel and chromium are inexpensive and abundant in nature, and it is intended to replace nickel and chromium with manganese and aluminum respectively.
In metallurgical industry, chromium element is capable of enhancing corrosion-resisting ability of stainless steel. Generally, stainless steel contains more than about 12% in weight of chromium that may form an oxidative layer to resist further oxidation.
Taiwanese Pat. Appl. Ser. No. 89121645 titled “low-density high-ductility iron-base alloy for a golf club head” discloses Fe—Mn—Al alloy having poor corrosion-resisting ability. In 5percent salt moisture testing standard, Fe—Mn—Al alloy containing chromium less than 5.5% in weight performs poor corrosion-resisting and cannot pass. On the contrary, Fe—Mn—Al alloy containing chromium more than 9.0% in weight may improve corrosion-resisting ability but it performs with high brittleness and poor ductility that deteriorates mechanical characteristic. In the light of this task, it is hard that Fe—Mn—Al alloy contains adequate chromium for improving corrosion-resisting ability. In order to maintain desired mechanical characteristic, it is necessary that a Fe—Mn—Al alloy surface must require plating for corrosion resisting.
In manufacturing a golf club head, Fe—Mn—Al alloy has highly low density, excellent vibration-absorbability and high degree of hardness. Casting a golf club head with Fe—Mn—Al alloy, the center of gravity of the golf club head may be lowered, and a striking surface area and dimensions of the golf club head may be increased. In use, inevitably, the golf club head made of Fe—Mn—Al alloy has poor corrosion resisting. To avoid rustiness or corrosion, there is a cladding material on the surface of the golf club head to reduce the possibility of rusting. In order to improve plating quality, there is a need for a series of preparing steps for pre-treating the golf club head. Consequently, it can insure a plating layer to securely adhere to the surface of the golf club head and to avoid peeling off therefrom.
Referring initially to FIG. 1, it illustrates a pre-treating method for plating an alloy surface. The pre-treating method includes the steps consisting of an ultrasonic energy cleaning step, a degreasing step, a deterging step, an electrolysis step, an activating step and a plating step.
In ultrasonic energy cleaning step, the alloy surface is cleaned with ultrasonic energy for preliminary removing larger grime.
In degreasing step, the alloy surface is subsequently treated with a chemical solution, such as sodium hydroxide, and soaked in the chemical solution for two minutes for removing accumulated grease. Then, the alloy surface is further cleaned in water.
In deterging step, the alloy surface is subsequently treated with an acid solution, such as 5%–30% of hydrochloric acid, for eliminating corrosion produced in previous high temperature conditions. Then, the alloy surface is further cleaned in water.
In electrolysis step, the alloy surface is subsequently treated with anodic electrolysis, such as 5%–90% of sulfuric acid in current density of 5–40 A/dm2, for removing an oxidative or inactive layer. Then, the alloy surface is further cleaned in water.
In activating step, the alloy surface is subsequently treated with an acid solution, such as 15 g/l–150 g/l of hydrochloric acid or sulfuric acid, for activating. Then, the alloy surface is further cleaned in water.
In plating step, the alloy surface is finally plated with corrosion-resisting metal.
The above-mentioned method is widely used and suitable for treating alloy steel or low-carbon steel. However, the above-mentioned method is unable to enhance adhesion of the plating layer to a Fe—Mn—Al alloy surface, and unsuitable for treating Fe—Mn—Al alloy. In electrochemical analysis, aluminum element contained in Fe—Mn—Al alloy is highly activated and easily oxidized to inactivate the Fe—Mn—Al alloy surface. In electrolysis step, when the Fe—Mn—Al alloy surface is treated with anodic electrolysis for removing an oxidative layer, aluminum element contained in Fe—Mn—Al alloy is soaked in a high-concentrated acid solution, and then an electric current is conducted in the acid solution. At this time, not only the original oxidative layer (Al2O3) may be remained on the Fe—Mn—Al alloy surface, but also more oxidative layers reacted with aluminum elements may be precipitated on the Fe—Mn—Al alloy surface. Consequently, the Fe—Mn—Al alloy surface is inactivated and unfavorable for plating process. Hence, there is a need for an improved pre-treating method for plating a Fe—Mn—Al alloy surface.
The present invention intends to provide a pre-treating method for plating a Fe—Mn—Al alloy surface which includes ultrasonic energy cleaning step, heat-degreasing step, ultrasonic energy deterging step and basic electrolysis step. In ultrasonic energy deterging step, the Fe—Mn—Al alloy surface is treated with a high-concentrated basic solution for removing an oxidative layer, and ultrasonic energy for speeding activation. Thereby, the Fe—Mn—Al alloy surface can provide activity and avoid inactivity for improving adhesion of a cladding material that may enhance plating quality and corrosion-resisting ability.